New VehicleLinkManager implementation

Clean up references to MainRootWindow globals

Unified photo/video control which works with mavlink cameras and just video stream

Rework Fly View into separate layers which can be customized at each layer.

More FlyView encasulation. Make QGCPipOverlay completely self contained

Fix video initialization - VideoReceiver did not start because sink was not created because videoBackgroundComponent was not loaded on startup if video was disabled

Disable video workaround for gstreamer crashes

Clip PIP window so when video is set to fit width, the hight is clipped
Remove ExclusiveGroup from CameraCalc radio buttons
Remove ExclusiveGroup from FWLandingPatternEditor radio buttons
Set main window minimum width and height

Adding mux GStreamer plugin libraries to Android (to enable video recording on Android)
Adding an option to limit the amount to disk used for saving videos
Adding an option to show/hide the REC button (allowing plugins to handle the recording in their own way)
Adding simple frame grab to file

Android done.

UI Tweaks for all mobile platforms.